1. Field of the Invention
The present invention relates to a method of preparing high purity 2,6-naphthalene dicarboxylic acid by dissolving 2,6-naphthalene dicarboxylic acid containing impurities, in particular, coarse 2,6-naphthalene dicarboxylic acid obtainable by oxidizing dialkyl naphthalene with molecular oxygen and by crystallizing the coarse 2,6-naphthalene dicarboxylic acid, the 2,6-naphthalene dicarboxylic acid being a useful compound to serve as a raw material for manufacturing resin, such as polyethylene naphthalate (PEN resin), exhibiting excellent functions.